X-ray system.



C. E. CAMPBELL..

X-RAY SYSTEM.

APPucATIoN min Ammo. 1916.`

Patented Aug. 1917.

L 5 0, 6 3 ow. l

` mined lengths of time. The chief object of` CHARLES E. CAMPBELL, 0F LYNN, MSSAGHUSETTS.

X-RAY SYSTEM.

To all whom t may concer/n:

Be it known that I, CHARLES E. CAMP- BELL, a citizen of the United States, residing at Lynn, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in X-Ray Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as lwill enable others skilled in the art to Which it appertains to make and use the same.

The present invention relates to an improvement in X-ray systems such as are employed for radiographing or for exposing objects of various kinds to the action of X-rays of a given intensity for predeterthe invention is to produce an X-ray system having provision by means of which the voltage across theX-ray tube, the current through the tube, and the length of time of the current flow, may be simultaneously regulated. The'result is that all objects of the same nature undergoingthe same mode of treatment for the purpose of being radiographed or for the purpose of being subjected tothe beneficial action of the X-rays, will be uniformly exposed to X-rays of such intensity and duration as have been found empirically to produce the desired results. Thus the results obtained by the use of the present invention will be uniform in quality. The specilic form or embodiment chosen to illustrate the principle of the invention is described in the followin specification as being especially adapted or radiographing parts of the human body.

The various parts lof the human body offer different resistances to the penetration of X-rays, and consequently, in order to make successful radiographs thereof, adjustments must be made for penetration, for the amount of current passing through the tube, and for the length of time the part of the body being radiographed is exposed to the action of the X-rays. Successful radiographing with the X-ray systems now com-v monly employd for the purpose requires a considerable amount of experience and skill on the part of the operator. The various adjustments as to penetration, current, and time of exposure, must be separately made. And, in spite of the fact that charts showing the various amounts o f kilo-volts or spark- Specification of Letters Patent. Patentgd Aug, 7, 1917,

Application led August 10, 1916. Serial No. 114,172. i

lengths, milliamperes, and time of exposure required are furnished with X-ray systems, successful radiographing is accomplished only after long experience. A further object of the present invention is to produce an X-ray system by means of which the process ofrmaking radiographs may be so simplified that any person of ordinary intelligence, and without previous experience, may make a successful radiograph simply by moving a selector arm to a point on a chart indicating the parts of the body to be radiographed, and by pressing a circuit closer. The movement of the selector arm simultaneously adjusts the voltage regulating means, the current regulating means, and the time ofl exposure regulating means. Among the various features by which this second object of the present invention is accomplished are those by which the penetration necessary for persons of heavy, medium, or light builds can be regulated. The X-ray system of the present invention is adapted for use in connection with either the ordi- 'showing their combination and coperation with the features of the invention.

In common with the usual X-ray systems, the X-ray system of the present invention comprises an X-ray tube, which may be either the ordinary gas tube or the electron discharge tube. The features of the present invention in coperation with an electron discharge tube will first be described, and then a description of their coperation with the ordinary gas tube will be given.

-'The X-ray tubes may be excited in any usual or preferred manner. In the drawing illustrating the application of the features of the present invention to an X-ray system,'the electron discharge tube is shown connected in full lines with the circuits. The necessary connections for operating the ordinary gas tube are shown in dotted lines. The source of alternating current of about 220 volts is indicated by the lines-,10 and 11,

25 the needle 25 isat either the points 1 orv2 These lines are in circuit with'l a step-up transformer, indicated at 12, of which the Y primary coil 13, of few turns, is in proper ratio with the secondary coil 14,'- of many turns7 for stepping up the current to the required voltages; The primary coil 13-is provided with adjustments or taps Aso that any desired variation of secondary potential may be obtained. Connected with a part of the secondary coil is a kilo-voltmeter for indieating the voltage produced. From the secondary coil 14 ofthe transformer 12 the current passes by way of the wires 16 and 17 to lstationary terminals adjacent a high tension rectifying plate 20, which gives the alternatin'g-current a unidirectional iow through the tube. The rectifying plate 20 is driven by a synchronous motor 18.` This motor may be of any usual or preferred construction suitable for the purpose.

The motor 18 is connected with the lines 10 and 11 by means of a motor switch 21.

A polarity indicator 22, connected with the motor 18, is used to indicate the polarity of the tube terminal wires 23 and 24, and when on the dial, thepolarity switch 26is closed on the corresponding poles 27 or 28, according to the' indication of the needle. In th1s way the proper polarity is secured, so long as the wire 23 is connected with the cathode and the wire 24 is connected with the anode. From the motor 18 the high tenslon current passes to the tube by way of the lines 23 and 24.l When an electron discharge tube is employed in connection with the system of the present invention, it is of I I course necessary to heat the cathode filament in vorder that the electrons therefrom may establish a path for the hi h tension to the anode. It is customary to cat the filament from a separate source, as, for example, a

battery. But, inasmuch as the volume of i the X-rays varies according to the temperavturco/fthe filament, and the .various parts offfthe body to be radiographed require different-penetrations, it is a feature of theinvention to control the heating of the filament in accordance with the' volume of' X-rays required. And for this purpose a filament transformer, indicated at 30, is provided, of which the primary coil 31, of many turns ofwire, receives the voltage of` 220 volts from the main lines 10 and 11 through the wire 32 connected with the line 11, and

. through the wire 33 connected with the part' lof the system forming the subject-matter of the invention, which will be presently described. The windings of the secondary coil 35 of the filament transformer arein Y proper ratio with the'windings of the pri` mary coil 31, in order to reduce the voltage of 220 volts to about 12 volts. .The secondv 'ary coil 35 is connected with the filament vthrough thewires 36 and 37. When the ordinary gastube is used, a switch 38 in the wire 33 is left open, and the wire 23 is directly connected with the tube, there being no connections in this case between the filament transformer and the Agas tube. The

v arrangement and operation of the parts just described as usual.

The apparatus or mechanism of the present inventiomadapted for coperative action with the X-ray producing parts just described, comprises a controlling device through which an electrical connection is radiographing, connections of less resistance than the resistances 42, as for example the .wire 36, are in circuit with the controlling device, so that these resistances 42 are, in practical effect, short-circuited from the controlling device. Opposite eachcontact 41 is `written or printed the name of ,one of the various parts of the body it has been found necessary or desirable to radiograph or treat with X-rays. Located on the opposite side of a commutator 44 is a corresponding series of contacts 45 arranged concentrically with the contacts 41. These contacts 45 are in electrical connection with the primary coil of the transformer 12. Located on an arc of less radius than the arc of the series of contacts 45 is a thirdl series of contacts 46, eachof which corresponds to one of the contacts 45 and to one of the contacts 41-' These contacts 46 are also concentrically arranged with the other two series of contacts and are electrically connected with the primary coil of the filament transformer 30. Located between the contacts 46 and the filament transformer 30I is a lilament current control resistance or impedancel coil 47 for v ously adjusting the voltage, the current, and

the length of time the tube is in operation. This controller, which may be of any construction suitable for the purpose, isV shown as a pivoted selector arm 50 having brushes 51, 52, 53, and 54. The current passes from theline' 10, through the switch 26 by way of the wire 55, to the brush 54, and thence through one 'of the` contacts 46 to the lilament transformer. When the electron dischargel tube 1s used, a switch 57 is closed,

and in this case the current `liows through described. From the switch 57 the current passes through the commutator 44 tothe rbrush 52, thence by the brush 53 to one of the contacts 45, and from it by way of either i the lines 60, 61, 6 2, or 63 to the primary coil of the-transformer 12.

It is assumed for the sake of illustration that it is desired to have a radiograph of the dorsal spine. The selector arm 50 will then be turned until the brush 51 is above the contact 41, opposite to the words Dorsal spine. The brush 53 will then be over one of the contacts 45, and the brush 54 will be over one of `the contacts 46, the corresponding contacts 0f the three concentric series of contacts lying on radial lines. Inasmuch as an electron discharge tubeis in use, the current will not flow through the control resistances 42. It will be observed that the brush 53 is over one of the contacts 45, which is connected with the line 60, marked 7 5,000 volts; that the line lcuts' into the primary 13 of the transformer 12, and that the ratio of the part ofthe primary that 4will be in use, to the secondary coil, will produce 7 5,000 volts in the secondary coil. It has been found from experience that 75,000 volts gives the required penetration in taking radiographs of the dorsal spin e. The brush 54 Vwill be over one ofthe contacts 46 connected with a wire 65, which cuts into the filament current control resistance or impedance 47 at such a point that it causes suiiicient incandescence of the filament to permit the passage of 75 milliamperes through the X-ray tube, it being found that radiographs of the dorsal spine require this amount of current through the tube. Moving the selector arm 50 into registration with the dorsal spine contacts does not bring the transformer 12 into electrical connection with the. lines 10 and 11, as will be found by tracing out the circuit. The filament, however, is energized. It is necessary that the filament circuit be closed before the high potential circuit, so that-the filament may reach its proper degree of incandescence in order to permit Vthe passage through the tube of the requisite amount of current; and when it is borne 'in mind that some exposures only require onetenth of a second, it will be seen that it is necessary that the filament circuit be closed before the high potential circuit is closed. rIhe high potential circuit is closed by pressing a starter switch 67.

Not only must the filament in the tube be heated to the proper point of incandescence, and the requisite amount of voltage energize the tube in order to get the proper penetration, but the time of exposure must b e carefully regulated. The means provided in the present X-ray system vfor regulating the Y ries ia cross-bar having bridging contacts 73 and 74 located at its outer ends. When the starter switch 67 is pressed, the current passing through the coil 7l raises the armature until the contacts 73 and 74 bridge the terminals 75 and 76, and 77 and 78 respectively, thereby permitting the vcurrent from the source of supply to pass through the transformer I2` and energize the tube. As the armature 70 rises to make the electrical connection just described, its upper end or head is engaged by a latch 81, and thereby` held raised, after the electro-magnet circuit is again opened by the release ofthe starting switch. The closing of the contact points 73 and 74 against their respective contacts causes the current to flow through the wire 82, and through the switch 83 to the solenoid coil 84 of the time-controller 68. From .the coil 84 the circuit passes by Way of the release the armature 70 and thereby permit it to break the connections between the contact points 73 and 74 and the contacts they bridge. The opening of the switch 69 may be hastened by means of a spring.

The length of exposure varies according to the portion of 'the body being radiographed, and it is therefore necessary to regulate the duration of the time that the automatic switch 69 shall be closed. The opening of this switch is controlled, as has been shown, by the upward movement of the armature 86, and the rapidity of this upward movement, and therefore the lengthv 'of time the switch 69 remains closed, is regulated by a plunger 904 attached to the lower end of the armature 86 and adapted to slide vertically in a dashpot 91. As-the plunger 90 rises in the dashpot 91, the vacuum produced retards the upward movement of the armature 86, and this vacuum, and consequently the rate of movement of the plunger, varies according to the adjustment of a tapered valve 93 connected to the lower end of a lever 94 fulcrumed at 95 on a projection from the dashpot. The upper end of the lever 94 is provided with a cam boss 97, adapted to be engaged by any oneof the .various projections 98 of ar cam disk 99,

,which is connected with the selector arm 50 and is rotated in timed relation therewith. The-projections 98 ofthe cam disk 99 are at various radial distances from the center of the cam. These projections98 thereby Airespondingly turned to present one of the cam projections 98 having the proper radial distance :for regulating the opening of the* valve 93, and thereby control the length .of exposure. The length of the taper of the l valve 93 aii'ords a very fine adjustment.

When a patient is to be treated for cancer or other ailments beneted by the prolonged action of X-rays, the time controller is rendered inoperative by opening the switch 83.

The selector arm 50 is then swung to registration with the contact 41 opposite the word Treatment. A It will be observed by an inspection of the diagrammatic view that the brush 54 will then be over Athe contact 46, which is so connected with the lament cur- 'rent control resistance that only four millianiperes are permitted to flow through the tube, and that the brush 53 will be over the contact 45 connected with the line .62 which cuts into the primary 13 at such a point that 90,000 volts are produced by the secondary` lNow when the starter switch 67' is closed,-

so that the coil 71 is energized to close the switch 69 and permit the current to pass through the transformer 12 to generate the X-rays, the switch 69 remains closed until a stop switch 101 is closed against the terminal E 102. The closing of the stop switch 101 causes the current to flow throughl the wire 103 to the. coil 104 surrounding an armature integral with the -trip rod 88. The energization of the coil 104 causes the trip rod 88 to rise and thereby trip the latch 81 and permit the switch 69 to be opened.

The use of the features of the present invention in lconnectionwith an electron d ischarge X-ray tube has just been described. If it is desired to employ the ordinary gas tube, the wires 23 and 24 will be connected with the terminals of 'the cathode and anode of the as tube, as indicated in dotted lines in the iagram. The wires 36 and 37 will then be dead-ended, and the switches 38 and 57 will remain open. Then, upon the movement of the selector arm 50 to 'the part of the body -to be. radiographed, and upon the clos` ing of the starter switch 67, the current will pass from thecontact 41, with which the selector' arm 50 `is in engagement, through lone ofthe lines 106 to .the miliampere control resistances 42. These resistances 42 are so adjusted that the proper amount of curr ren't will pass through the tube for the generation ou X-rays o the required intensity according to the penetration desired, when the vacuum of the tube has been .so regulated that the kilo-voltmeter indicates the voltage required.' In case of the use of an ordinary gas X-ray tube, it will be observed that the current is controlled by the resistances 42 and that 'the voltage is regulated in exactly the .same manner as in the case of the use of the electron discharge tube.. Whereas, when the latter tube isused, the current supply necessary .to heat the iilament vis regulated by the vresistance 47. Y

The eXtra resistance 59 is in continuous sol circuit with the system, whether'the electron dischargetube or the gas tube is employed. This "resistance 59 is provided so that by ychoking back the current a lesser ei'ect on the X-ray plate can be secured if desired. An adjustable switch or voltage regulator 108 is movable into contact with the terminals 109, 110, and 111, which cut into the primary of the transformer 12 at various points, and thereby afford' provision for compensating for line drop. Usually when the X-ray apparatus is installed, a single adjustment of the voltage regulator is suiicient.

According as the patient who is to be treated or radiographed varies in build, that is, whether he is stout, medium, or thin, the penetration of the X- rays should vary. For the purpose of regulating the amount of penetration for such cases, a voltage controller 112 is provided which is adapted'to contact with the terminals 113, 114, and 115, which cut into the primary of the transformer 12 at various points, in order to con# trol the amount of'voltage produced by 'the secondary.

given in connection with its use in making a j radiograph of'the dorsal spine, and in the case of a treatment. It will' be observed Jfrom an inspection of the diagram that according as the selector arm is moved into alinement with one or another ofthe con'- tacts opposite which the names of the various parts of the body are placed, different voltages will be produced by 'the transformer to regulate the intensity of the X-rays. It will' be observed further that the amount of current permitted to iow through the filaamount of current permitted to pass through the vacuum of a gas tube are automatically regulated bythe same movement of the se lector arm, by having the wires leading from the various contacts cu't into the milliampere control resistances 42 and into the filament e control resistance 47 at various pomts.v It

will be understood that the figures indicating the voltage and the current required for takl ing a radiograph of a. particularpart of the ment of an electron discharge tube and the 1 20 incensi from thetube. ,If this distance is lessened or increased, a corresponding change in the time regulation of the system must be allowed for. l

In the foregoing description of the illustrated embodiment of the present invention, the features thereof have been described as especially coperating for radiographing parts of the human body. It will be understood, however, as pointed out in 'the introv ductory statement of the specification, that the invention is not limited to this use, but

may be applied to any purpose for which an' X-ray apparatus is employed where it is essential to regulate the voltage across the tube, the current through the tube, and the length of time the tube is in operation. Thus, where it is desired to make an X-ray treatment on any object, whether organic or mineral, at a certain voltage and current, and for a predetermined length of time, a chart may be prepared bearing the names of the objects tobe exposed to the action of the X-rays. It having been lirst determined empirically how long the object should be exposed for a certain purpose to an X-ray action of certain intensity, a movement of the controller or selector arm to the name of the object to be treated, and the closing the starting switch, will give the. requisite exposure and thus insure a uniform result on all the objects subjected to the same treatment. Accordingly, the features of the inlventicn may be embodied in other forms and applied to purposes other than those shown and described, without departing from the spirit of the following claims.A

Having thus described the invention, what is claimed iszl 1. An X-ray system having, in combination,44 an X-ray tube, a source of current for exciting the tube, means for regulating the voltage across the tube, means for regulating the amount of current passing through the tube, means for regulating the time of the current flow, and means for simultaneously adjusting all three regulating means.

2. An X-ray system having, incombination, an X-ray tube, a source of current for exciting the tube, means for regulating the voltage across the tube, means for regulating the amount of current through the tube, and means 'for simultaneously adjusting the two regulatin means.

' 3. An -ray system having, inrcombination, an X-ray tube, a source of current' for exciting the tube, means for regulating the amount of current passing through the tube, means for regulating the time of the current How, andgmeans for simultaneously adjusting the two regulating means.

4. An X-ray system having, in combination, an electron discharge X-ray tube, a source -of high potential for produclng X-rays in the tube, means for regulating the incandescence of the filament, means for regulating the potential across the tube, means for regulating the time the tube is in operation, and means for simultaneously adjusting the three regulating means.

5. An X-ray system having, in combination, an electron discharge X-ray tube, a

source of high potential forl exciting X-rays in the tube, means for regulating the incandescence of the lament, means for regulating the potential across the tube, and means for simultaneously adjusting the two regulating means.

6. An X-ray system having, in combination, an X-ray tube, a source of current for exciting X-rays in the tube, means for regulating the voltage across the tube, means for regulating the amount of current through the tube, a series of contacts connected with the voltage regulating means, a second series of contacts arranged correspondingly to the first series connected with the current regulating means, and means for electrically bridging the space between a contact of the first serles and the corresponding contact of the second-series.

^ 7. An X-ray system having, in combination, an X-ray tube, a source of current for exciting X.rays in the tube, means for regulating the voltage across the tube, means for regulating the amount of current through the tube, means for electrically connecting the current regulating means and the voltage regulating means, and means connected with the last named means and simultaneously operating therewith for controlling the duration of current flow through the tube.

8. An X-ray system having, in combina- Y tion, an X-ray tube, a'source o-current for l parts of the body as it 1s desired to radiograph, a selector arm for movement into position opposite the name of the part to be radiographed, and connections between the selector arm when itA has been so moved and ios the three regulating means for simultaneously adjusting the latter. v

9. An X-ray system having, in combination, an X-I'ay tube, a source of current for j exciting the tube, a chart whereon are listed the names of parts of the body to be radiographed, means for regulating the voltage across the tube having leads terminating opposite the names, means for regulating the amount of current passing through the tube having leads terminating opposite the names, a selector arm for movement opposite the names having provision for bridging leads opposite the mame with which the selector arm registers, and means connected with the selector arm for regulating the duration of current oW.

10. An X-ray system having, -in combination, an X-'ray tube, a source of current for exciting the tube, a chart on'which are listed .thenames of parts of the body to be radiographed, a selector arm for movement into registration'with the name of the part to be radiographed, means connected with the see lector arm" for determining the time the X-ray circuit shall be in operation, and means controlled by the movements of the selector arm for regulating the voltage across and the current through the tube.

-11. A11 X-ray system having, in combination, an X-ray tube, a source of. current for exciting the tube, a chart on which are listed thenames of parts of the body to be radiographed, ya selector arm for movement into registration with the name of the part to be radiographed, and means connected with the selector arm for determining the time the i justing all three regulating means, and separate' additional means for regulating the voltage across the tube.

13. An X-ray system having, in combination, an X-ray tube, a source of current for exciting the tube, and means for simultaneously regulating the voltage across the tube, the amount of current passing through the tube, and the time of' the current flow.

14. An X-ray system having, in combinationan X-ray tube, a source of current for exciting the tube," means for simultaneously regulating the voltage across the tube, the

current passing through the tube and the length of time of the current flow, and separate additional means for regulating the voltage across the tube.

15. An X-ray system having, in combination, an X-ray tube, a source of current for exciting the tube, a chart Whereon are listed names of objects to be exposed to the action of the X-rays, means for regulating the voltage across the tube having leads corresponding to th names, means for regulating the amounI f of,currentv passing through the tube having'le'ads corresponding to the names, a

' regulating means controllerladapted to be movedv opposite the names, having provision for bridgingthe leads corresponding to the name with which the lcontroller registers, and means connected with the controller for regulating the durationpf current flow.

y CHARLES E. CAMPBELL.

tov 

